1. Field of the Invention
This invention relates to a straddle type vehicle such as a motorcycle, for example.
2. Description of Related Art
Conventionally, in straddle type vehicles such as motorcycles etc., the so-called under bone type frame structure is known (See Patent Documents 1 and 2, for example). In straddle type vehicles having the under bone type frame structure, an area extending in front of the seat is greatly recessed to define a relatively large space in the front area of the seat. A rider thus can easily get on and off the vehicle.
On the other hand, in order to ensure such a large space in front of the seat, some ideas are necessary for layout of an engine and auxiliaries. Particularly, an air cleaner needs to be well considered about its positioning location and layout of its air inlet port, because the air cleaner is a component having a large capacity.
The motorcycle disclosed in Patent Document 1 includes a main frame obliquely extending downward rearward from a head pipe, and a rear frame obliquely extending upward rearward from a rear portion of the main frame. An engine is supported by the main frame under a suspended condition. A fuel tank and a seat are mounted on the rear frames. An air cleaner is positioned below a forward end of the main frame so as to avoid the recessed portion.
The motorcycle disclosed in Patent Document 2 includes a main frame obliquely extending downward rearward from a head pipe, and seat rails obliquely extending upward rearward from a rear portion of the main frame. Similarly, an engine of this motorcycle is supported by the main frame under the suspended condition, and a fuel tank and a seat are mounted on the rear frames. On the other hand, in this motorcycle, an air cleaner is positioned in the rear of the engine and below the seat rails so as to avoid the recessed portion.
Patent Document 1 is WO 03/001048, Pamphlet, and Patent Document 2 is JP-A-2002-37170, Laid-open Patent Application Publication.
However, in the motorcycle disclosed in Patent Document 1, because the air cleaner is positioned below the forward end of the main frame, consequently, the air cleaner is positioned in the vicinity of a front wheel. Therefore, when mud, water or the like is raised up by the front wheel, the mud etc. is apt to be sucked into the air cleaner.
On the other hand, in the motorcycle disclosed in Patent Document 2, because the air cleaner is positioned in the rear of the engine and below the seat rails, consequently, the air cleaner is positioned in the vicinity of a rear wheel. Therefore, when mud, water or the like is raised up by the rear wheel, the mud etc. is apt to be sucked into the air cleaner.